Research On The Control Software Development And Integration Test Of LKA And LC System

In recent years,research on Advanced Driver Assistance Systems has emerged in an endless stream.Longitudinal assisted driving systems have become more mature than lateral assisted driving systems.Research on lateral assisted driving systems is also being increasingly strengthened.The data shows that the lateral assisted driving system has great significance for the safety of the car,and it also has a positive effect on liberating the driver’s physical and mental stress.As a subsystem of the Advanced Driver Assistance Systems,Lane Keeping Assistance system enables the driver to avoid the risk of accidental traffic accidents due to distraction.Lane Centering system as a higher-level system of the Lane Keeping Assistance system can make the driver drive the vehicle more relaxed,which is of great significance to the safety of the car and the comfort of the driver.The ISO standard imposes requirements on the maximum values of the lateral acceleration and the lateral acceleration derivative when LKA acts.The paper proposes that starting from linear two degrees of freedom,when the vehicle speed is constant,it can be considered that the vehicle’s lateral acceleration is proportional to the steering wheel angle,the lateral acceleration derivative,and the steering wheel speed in the steady state.Based on this,after selecting the principle of the fastest correction,the mode of steering movement of the steering wheel when the LKA is active is designed.The paper also developed a lane departure calculation module and a deviation threshold decision module based on the RTW camera controller output information,thus completing the design of the LKA master control strategy architecture.Applying the prediction theory,feedforward control and feedback control,the paper also developed the LC control algorithm,whose output is the desired steering wheel angle.Using the torque control interface provided by the EPS controller,the LC controller realizes the control of the turning angle of the steering wheel.The strategy of development was simulated and verified by using CarSim/Simulink co-simulation.The control strategy of the system was simulated using the built-in auto-driving hardware-in-loop simulation platform.Based on the analysis of the status quo of the Lane Keeping Assistance system and the Lane Centering system,the active steering control algorithm based on the EPS torque interface is designed by the three-step method,and the position following controller is designed to realize the position control through the torque interface.Through the angle decision module,real-time calculation of the data collected by the sensor is performed,and the desired steering angle of the steering wheel is output.The steering wheel torque corresponding to the desired position of the steering wheel output and the steering wheel is applied to the steering column via the EPS to make the steering angle of the steering wheel follow the angle decision controller decides the desired angle.This paper also compares the position control and the torque control of the steering system,analyzes the advantages and disadvantages of the two control methods,and verifies the advantage and necessity of using the designed position following controller to achieve position following.The position-following controller designed with Triple-step Method is compared with the traditional PI controller and the traditional feedforward plus feedback controller.Advantages and effectiveness of The Triple-step position following controller is verified by comparing the simulation curve and experimental results..An active takeover strategy for the lateral assisted driving system was designed.The calibration parameters of the active takeover strategy in the system were adjusted,and the entire system was tested for integration.The active takeover strategy was verified on the Hardware-In-Loop test bench.